文摘
We synthesized four diphenylquinoxaline derivatives (SQs) with phenyl-thioether units, which combine photo-cleavable and hydrogen-abstracting groups in one molecule. The photochemistry and photopolymerization of SQs were investigated. SQs possess suitable UV−vis absorption in the range of 350−400 nm with high extinction coefficients. UV−vis and HPLC-MS spectra revealed that CS bond in phenyl-thioether group of SQs can be broken by irradiation of UV-light. Photolysis and photopolymerization experiments showed that SQs can be used as photo-cleavable photointiators, their photoinitiating efficiency can be enhanced by hydrogen donor. As photo-cleavable photoinitiators, SQs could initiate hexamethylene diacrylate (HDDA) very efficiently with the double bond conversion (DBC) of 80%. In the presence of ethyl-4-(dimethylamino) benzoate (EDB) as coinitiator, photoinitiator systems initiated photopolymerization of commercial acrylate monomers with higher double bond conversion than 90%. These characteristics make SQs potential photoinitiators in photo-curing field.